Among batteries or cells having an electrode produced using a nickel powder such as Ni--MH batteries, there are those which have attracted attention because they do not contain elements controlled under an environmental pollution regulation, have density sufficient to generate high energy and are interchangeable with existing secondary batteries.
Proposed methods for producing these batteries are, for example, (a) a method comprising integrally combining a powder predominantly containing an active material with a current collector using a polymer binder, (b) a method comprising applying a paste of a powder predominantly containing an active material to a substrate of foamed nickel or fibrous nickel and subjecting the substrate to pressure molding, and (c) a method comprising integrally uniting a powder predominantly containing an active material with a current collector under compression using a nickel carbonyl powder.
However, the proposed methods have problems. The method (a) requires a polymer binder which offers electrical resistance to current flow, resulting in the reduction of high discharging capability. The method (b) necessitates an expensive foamed nickel or fibrous nickel substrate, leading to a high production cost. The method (c) presents a problem of low binding power which makes the powders easily removable.